Abstract: Disclosed herein are system, method, and computer program product embodiments for summarizing large histograms. In an embodiment, a client device may not have access to a full dataset stored in a secure system due to privacy or confidentiality restrictions. The secure system, however, may grant the client device access to a histogram related to the dataset as confidentiality may be maintained. Using this histogram, the client device may summarize the dataset to more efficiently utilize memory resources and/or more quickly execute queries. In an embodiment, the client device summarizes the original histogram into a form having fewer buckets than the original histogram. The client device also calculates new bucket boundaries using pairwise comparison and/or maxdiff algorithms.